Variable angle twin fluke anchor

ABSTRACT

An anchor of the twin fluke type has stocks of substantial breadth to promote even penetration of the flukes, the flukes being pivotally mounted with reference to the shank, and a resiliently yieldable member tending to hold the flukes in a first angular position which favors initial penetration of the flukes in the bottom. The resilient member is yieldable to permit the attainment of a larger predetermined angle which is better adapted for setting the anchor in the bottom after the initial penetration has been effected.

United States Patent 1 1 Hungerford 1451 Sept. 11,1973

[ VARIABLE ANGLE TWIN FLUKE ANCHOR [75] Inventor: Daniel Comstock Hungerford, North Palm Beach, Fla.

[73] Assignee: Brunswick Corporation, Skokie, 111. 221 Filed; Sept. 3,1971

21 Appl. No.: 177,550

[52] us. c1. 114/200 51 1111.01 B63b 21/44, B63b 21/46 [58] Field 01 Search 114/200, 207, 20s

[56] References Cited UNITED STATES PATENTS 2,711,150 6/1955 Ogg 114/208 2,987,028 6/1961 Fair 2,994,292 8/1961, Winslow .:::.114/208R 3,527,187 9/1970 Towne 114/208 R Primary ExaminerMilton Buchler Assistant ExaminerGalen L. Barefoot Att0rney-A. Yates Dowell, Jr.

[57] ABSTRACT An anchor of the twin fluke type has stocks of substantial breadth to promote even penetration of the flukes', the flukes being pivotally mounted with reference to the shank, and a resiliently yieldable member tending to hold the flukes in a first angular position which favors initial penetration of the flukes in the bottom. The resilient member is yieldable to permit the attainment of a larger predetermined angle which is better adapted for setting the anchor in the bottom after the initial penetration has been effected.

9 Claims, 13 Drawing Figures PAIENIEDSEH H975 3.757, 727

sum 2 BF 4 INVENTOR Daniel illzuz rerfaraf PATENIEB 9 3 SHEU 3 0F 4 INK ENTOR iycv'ford A Y 1 d, 15,4 7

ATTORN5 Daniel 6. Ha

VARIABLE ANGLE TWIN FLUKE ANCHOR BACKGROUND OF THE INVENTION This invention relates to ships anchors and more particularly to those of the twin fluke type, which have been in use for many years.

An anchor must be relatively lightweight and able to sustain a pull of many times its own weight. It must be capable of becoming firmly engaged or set in the underwater bottom and of being disengaged when desired.

Problems arise due to the irregularity of configuration of the bottoms and of the varying degrees of consistency.

When an anchor of this general type is thrown overboard it frequently does not land on a flat bottom. An irregular surface will therefore tend to tilt the anchor to one side. When the pull load is applied to the shank of a tilted anchor only one fluke tends to penetrate and this causes the other fluke to rise away from the bot tom, thus resulting in the failure of the higher fluke to penetrate or in uneven penetration of the flukes. Such uneven penetration is undesirable for a lightweight anchor since the latter is dependent on the area of the flukes in contact with the bottom for its load holding capacity.

Another problem is the difficulty in penetrating various types of bottoms. The tendency of the flukes to penetrate is dependent upon the angle between the shank and the flukes. However, an angle which is favorable for penetration may not be the optimum angle for the anchor to hold after penetration has occurred. Thus, anchors have been constructed in which the angle between the flukes and the shank is fixed or these are pivotally connected so that the angle may vary between zero and a predetermined maximum. When an anchor of either type is dropped, the flukes assume the position of maximum angularity with the shank; This position may be satisfactory for holding after penetration has occurred, but may not favor the initial penetration. For example,when the bottom is hard sand and the angle between the flukes and the shank is that commonly used, 32, substantial penetration may be impossible due to the anchor standing up on the fluke ends and plowing along the sand. It has been found that in such condition, if the angle between the flukes and the shank is reduced, penetration may be accomplished.

On the other hand, if the angle between the flukes and the shank is fixed at a substantially smaller angle, it may not effectively hold in such sand nor in a softer bottom. Hence, there has been a need for an anchor in which the angle between the flukes and the shank is temporarily maintained during initial penetration at a smaller angle than that which is the optimum for holding after the anchor is set.

Another problem in connection with anchors is their storage on board ship. Lightweight anchors of the type presently used commonly have fixed stocks extending perpendicular to the shank which are of considerable length, which are therefore difficult to store out of the way on board shipQAccordingly, there is a need for an anchor in which the length of the stock is not sacrificed but which may be moved out of the way for storage.

Furthermore, since the flukes of an anchor are relatively sharp, it is. desirable that the anchor be stored in such a positionthat the flukes do not protrude outside of the plane of the shank in order-to avoid unnecessary hazard or injury to the deck from the points during storage.

Another problem with prior anchors is that the flukes have generally been connected at their lowermost extremity to the stocks. This results in the flukes being loaded their entire length. However, it has been found that if the flukes are mounted on a rotatable shaft a substantial distance from their lower ends that they may carry a heavier load than if they are mounted in the previously described manner.

SUMMARY OF THE INVENTION AND OBJECTS Accordingly, it is an object of the invention to provide an anchor of the lightweight twin fluke type which is constructed so that the initial angle for penetration is substantially less than that for final holding.

A further object is the provision of an anchor of this type in which a pair of adjustable support members are so constructed that the flukes tend to penetrate evenly instead of having one penetrate more than the other if the bottom is uneven.

A further object is the provision of an anchor of this type in which the flukes are mounted on the crown in a position spaced from the bottom of the flukes in order to increase the holding capacity.

A further object is the provision of an anchor of this type in which a pairof support members and the crown cooperate for holding the flukes substantially in the plane of a shank when the anchor is stored on a horizontal surface, and in which the support members are movable to a position in which they occupy less space than when fully extended.

A further object is the provision of an anchor of this type in which the support members are of extended width in order to avoid tilting of the anchor when it reaches the bottom and thereby assure even penetration of the flukes, the stock extension being shiftable rearwardly in order to permit maximum penetration of the flukes.

A further object is the provision of an anchor of this type in which the shank has a movable ring for connection with the anchor line and which is slidable toward the rear of the shank in order to engage the crown to facilitate pulling the flukes out of the bottom.

BRIEF DESCRIPTION OF THE DRAWINGS These and other objects of the invention will become apparent from the description in conjunction with the accompanyingdrawings in which:

FIG. 1 is a perspective illustrating an anchor in accordance with the present invention and in particular the upper portion thereof;

FIG. 2 is a perspective of an anchor as viewed from the aft portion;

FIG. 3 is plan view, illustrating the adjustable support members in various positions;

FIG. 4 is a side elevation illustrating the anchor in the position for storage; FIG. 5 is an end elevation illustrating the adjustable support members in extended position;

FIG. 6 is a section to enlarged scale on the line 66 of FIG. 4;

FIG. 7 is a section to enlarged scale on the line 7--7 of FIG. 5;

FIGJS is a side elevation, with the adjustable support members omitted for clarity, illustrating the position of the anchor when it initially comes to rest on a bottom;

FIG. 9 is a view similar to FIG. 8 illustrating the angular position of the shank and flukes during initial penetration;

FIG. 10 is a view similar to FIG. 8 illustrating the final angular relationship of shank and flukes;

FIG. 11 is a relative perspective illustrating a modification;

FIG. 12 is a fragmentary side elevation of FIG. 11; and

FIG. 13 is a side elevation of the device being used.

DESCRIPTION OF THE PREFERRED EMBODIMENT With further reference to the drawings, the anchor of the present invention is of the relatively lightweight twin fluke type and includes a shank 10, crown 11, substantially triangular flukes 12 and 13 mounted on shaft 14 and a pair of adjustable support members 15 and 16, respectively, mounted on the outer sides of the flukes.

The shank is formed of rod material bent upon itself in a U-shape to form the sections and 21. A ring 22 is engaged with the shank and shiftable from a load position at the bight 23 to a lifting position adjacent to the crown (FIG. 10). The crown I1 is of rectangular boxlike configuration and receives the ends of the rod portions of the shank.

In order to mount the rods on the shaft 14 a pair of U-shape bracket members 24 and 25 are fastened, as by welding, to the opposite sides of the rod portions 20, 21 within the crown 11. The brackets have a central portion 26 and upstanding flange 27 at each side to provide added rigidity. An aperture 29 is provided through the centers of the portions 26 and of such size to permit pivotal movement of the shaft 14.

Shaft 14 is connected by welding 28, or the like, to the flukes l2 and 13. The flukes have side flanges 12' and 13' extending perpendicularly to the main body of the flukes and connected at their lower portions to the side walls of the crown 11. For balance, fluke 12 is mounted under-the shaft and fluke 13 over the shaft, as indicated in FIG. 6. At their lower ends the flukes have flanges extending perpendicularly to the main body, the flange 12" extending upwardly and the flange 13" extending downwardly as illustrated, for example, in FIG. 2. i

As indicated, the flukes are'mounted on the shaft at a distance spaced substantially from theirlower ends. The adjustable support members 15 and 16 are of substantially triangular or stirrup configuration, having a main central portion 30, converging side portions 31 and 32, and closely spaced mounting portions or ears 33 and 34. The mounting portions are pivotally connected by fastening means 35 to the sides of the respective flukes and in line with the shaft 14. The connection is snug in order that the support members will not swing freely. Dimples 36 in ears 33 mayengage openings 37 in flukes 12 and 13 in order to yieldably hold the flukes in outwardly extended position as in FIG. 1, for example. I I i Mounted on the top and bottom of the crown, as viewed in FIG. 7, and extending slightly below it, is a relatively stiff leaf spring member 40 which is connected to the crown by suitable fastening means 41 and flat metal holding element 42. With particular reference to FIG. 7, the spring member in a preferred embodiment is a flat, relatively thick bar of a plastic such as nylon which is sufflciently stiff to hold the flukes and shank in the position of FIGS. 2 and 9 under ordinary no load or low load conditions. This permitsthe anchor when it initially engages the bottom to have the flukes held at an angle which promotes their penetration into the bottom instead of plowing along without substantial penetration. However, as the tension on the line increases due to the engagement of the flukes with the bottom, the leaf member 40 yields to a final position as indicated in FIG. 10.

The leaf member must be of a material that can withstand repeated loads and which will return to its initial position within a reasonable time. A tough plastic material, such as nylon, has been found to be suitable. It is contemplated that other materials and other types of springs might be used. It has been found that a nylon spring of the type illustrated after being deformed in loaded position for a substantial time, when unloaded, returns approximately 50 percent immediately, approximately percent in an hour, and completely within a few hours.

When the anchor is dropped overboard, but before reaching the bottom, the flukes initially assume the angular position indicated in FIG. 2 in which the lower end of one rod section of the shank engages the adjacent spring member 40. When the anchor reaches bottom, the projecting portions of the adjustable support members 15 and 16 tend to support the anchor in a level position so that the points of both flukes may simultaneously engage the bottom, the crown raising its after portion and permitting the flukes to tilt slightly as in FIG. 8. As a force is applied by the line upon the anchor, it again assumes the angular position of FIG. 2 and FIG. 9 in which the shank is restricted by the spring member from reaching an angular position, with reference to the flukes, greater than that indicated in FIG. 9. This angle X may be selected in accordance with the general type of bottoms anticipated, in the range between about 6 and 32. A good working angle for hard, sandy bottoms has been found to be approximately 20.

Whenthe pull upon the ring increases, the flukes penetrate the bottom and the spring member permits the angle between the shank and the flukes to be increased to the maximum angle Y as indicated in FIG. 10. Upon further penetration of the flukes, the support members may pivot aft as indicated in FIG. 3 to permit maximum penetration. The angle for maximum holding is generally recognized to be approximately 32.

When the anchor is desired to be removed, the force is applied in such direction as to pull the ring back to the position indicated in phantom in FIG. 10 at which time it engages the crown and withdraws the flukes from the bottom.

When the anchor is placed on deck in position for storage, the support members 15 and 16 are retracted to the position of FIG. 4 in which the lower portions of such members. and the crown cooperate to hold the flukes substantially in the plane of the shank as indicated in FIG. 4, thereby avoiding contact of the points with the deck or projecting upwardly to constitute a safety hazard.

In the modification of FIGS. 11-13, the spring members extend forward from the crown instead of aft as in the previously described embodiment. Thus the crown 51 from the side is generally trapezoidal having side walls 52, 53 connected to upper and lower walls 54 and 55, respectively. Upper and lower spring members 56, 57 are connected to the upper and lower walls, respectively, by suitable fastening means 58 and flat metal holding elements 59, 60.

The spring members extend forward of the crown and engage the shank portions or 21 as the shank pivots with respect to the flukes. The spring is of such nature that it will hold the flukes in an initial predetermined relationship with respect to the shank but will yield to an optimum anchor holding position as indicated in FIG. 13.

What is claimed is:

1. An anchor comprising an elongated shank having forward and aft ends, a crown pivotally mounted on said shank adjacent to the aft end of said shank, first and second flukes mounted on opposite sides of the crown, support means extending outwardly from each fluke, and resiliently yieldable means on the crown and engageable by the shank to hold the shank in a predetermined initial angular relationship with the flukes during initial penetration of the flukes into a bottom, said yieldable means permitting the angular relationship to increase in proportion to an increase in load on the anchor following such initial penetration.

2. The invention of claim 1, in which said resiliently yieldable means and the aft end of the shank extend aft of the crown, and said end engages said yieldable means as the shank pivots with respect to the flukes.

3. The invention of claim 1, in which said resiliently yieldable means extends forward of the crown and engages the shank as the shank pivots with respect to the flukes.

4. The invention as described in claim 1, in which the shank is constructed of parallel bars, and a ring which is slidable between the bars from the crown to the forward end.

5. The invention of claim 10, in which said resiliently yieldable means constitutes first and second leaf spring members.

6. The invention of claim 5, in which each of the leaf spring members is a bar of nylon.

7. The invention of claim 1, in which the crown and flukes are mounted on a shaft which is pivotally carried by the shank, and in which the flukes are mounted on the shaft with a substantial portion of their aft ends on the other side of the shaft from their forward ends.

8. The invention of claim 1, in which said support means are pivotally mounted on the flukes about an axis which is perpendicular to the axis of pivoting of the crown and the shank, whereby they may be retracted toward the forward end of the shank for storage, extended outwardly when the anchor is dropped to insure even penetration of the flukes, and moved aft in order to permit maximum penetration of the flukes.

9. The invention of claim 8, and means tending to hold said support means in the outwardly extending position. 

1. An anchor comprising an elongated shank having forward and aft ends, a crown pivotally mounted on said shank adjacent to the aft end of said shank, first and second flukes mounted on opposite sides of the crown, support means extending outwardly from each fluke, and resiliently yieldable means on the crown and engageable by the shank to hold the shank in a predetermined initial angular relationship with the flukes during initial penetration of the flukes into a bottom, said yieldable means permitting the angular relationship to increase in proportion to an increase in load on the anchor following such initial penetration.
 2. The invention of claim 1, in which said resiliently yieldable means and the aft end of the shank extend aft of the crown, and said end engages said yieldable means as the shank pivots with respect to the flukes.
 3. The invention of claim 1, in which said resiliently yieldable means extends forward of the crown and engages the shank as the shank pivots with respect to the flukes.
 4. The invention as described in claim 1, in which the shank is constructed of parallel bars, and a ring which is slidable between the bars from the crown to the forwarD end.
 5. The invention of claim 10, in which said resiliently yieldable means constitutes first and second leaf spring members.
 6. The invention of claim 5, in which each of the leaf spring members is a bar of nylon.
 7. The invention of claim 1, in which the crown and flukes are mounted on a shaft which is pivotally carried by the shank, and in which the flukes are mounted on the shaft with a substantial portion of their aft ends on the other side of the shaft from their forward ends.
 8. The invention of claim 1, in which said support means are pivotally mounted on the flukes about an axis which is perpendicular to the axis of pivoting of the crown and the shank, whereby they may be retracted toward the forward end of the shank for storage, extended outwardly when the anchor is dropped to insure even penetration of the flukes, and moved aft in order to permit maximum penetration of the flukes.
 9. The invention of claim 8, and means tending to hold said support means in the outwardly extending position. 